Friday, October 16, 2009

Generic Repository - Generic DB access?

Generic Repository (grepo) is an open source (ASLv2) framework for Java which allows you to access (database) repositories in a generic and consistent manner.

The main features of the framework are:
* generic support for Hibernate based DAOs
* generic support for Jpa based DAOs
* generic support for executing database stored-procedures and functions
* highly customizable

The "Generic Query" component allows to access databases using SQL queries. Currently the following ORM (Object Relational Mapping) tools/APIs are supported:

* Native Hibernate API
* Java Persistence API

The "Generic Procedure" component allows to access databases using PLSQL (that is calling stored procedures and/or functions) without requiring custom implementations - gprocedure is build on top of the Spring (JDBC) framework.

Daniel Guggi

The Generic Repository Framework (grepo) has its origins back in 2007. I started development after reading Per Mellqvist's article "Don't repeat the DAO". My employer BearingPoint INFONOVA GmbH develops and maintains various business applications for its customers (mainly telecom providers). The software is developed/extended by various development (scrum) teams. Even though we have a professional development environment (using professional/good tools and frameworks etc...) and development guidelines (detailed coding conventions etc...) it turned out that the data access layers in our software products got quite fragmented, inconsistent and bloated - mainly because of big development teams and large software products, the typicall daily project-stress and the always reoccoring (similar) boilerplate code for database access logic. So we started developing a framework which in turn was tuned and improved in order to achieve the following main goals for our software products:

* Ensure coding conventions and guidelines.
* Avoid boilerplate code for database access logic.
* Improve development time and code quality.

Finally we came up with a framework based on Spring and Hibernate. The framework is integrated in our software products for quite a while right now and is used for basically (at least about 90%) all new database related access objects. We are quite happy with the result and thus we decided to make it open source - and so the Generic Repository project was born.

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